3
class periods to explore the properties of enzymes, models of enzyme action
and the factors that affect rate of enzyme activity

b) Part 2

2class periods to formulate a testable hypothesis
and design an experimental procedure

2
class periods to conduct the inquiry based lab
activity

1class period to present data and results to the
class

Purpose:Students
investigate factors that affect the rate of enzyme action.Catalase will be used as the model enzyme to investigate the factors that
affect rate of enzyme action.

Objectives:
Students will be able to (SWBAT):

develop an understanding of the structure and function of enzymes

understand how the shape of an enzyme is related
to its function

describethe characteristics of enzymes

explain
the lock and key and induced fit models of
substrate binding

use
appropriate scientific terms to describethe functions of an enzyme, such as substrate, product,activation energy, active site and enzyme-substrate
complex

determine
the factors that affect the rate of enzyme
activity

explain
how each factor (ie. pH, temperature,
concentration of enzyme/substrate) alters the rate of enzyme activity

formulate
a hypothesis about the environmental factors that
will alter the rate of enzyme activity

design
an experiment to test their hypothesis

collect
and analyze data as well as draw valid
conclusions from data

present
their experimental findings to the class by
creating a poster

Prior Knowledge:
Students will have an understanding of the four
classes of biologically important compounds (ie. carbohydrates, fats, proteins
and nucleic acids).In particular,
students will have an understanding of the different levels of protein structure
as well as the various functions of proteins

Essential
Questions:

What
is an enzyme? How do enzymes affect a chemical
reaction?

What
are the general characteristics/properties of
enzymes?

Describe
the two models used to explain the catalytic
activity of enzymes

Explain
how changes in enzyme or substrate concentration
affect an enzyme's behavior?

Preparation and Procedure:

Part 1: WebQuests (3 class periods)

1.
Students will complete a K-W-L chart on enzymes.

2.
Students will work in groups of two or three to complete WebQuests that explore
the

a)structure and function enzymes.

b)models used to explain the catalytic activity of enzymes (ie. Lock and Key and
Induded Fit models).

c)characteristics of enzymes.

d)factors that affect the rate of enzyme activity.

3.
Use the Essentials Questions to guide
students during the WebQuest.

4.Teacher Tip:

a)
Print out hard copies of each of the websites used for the WebQuests in the
event that students are unable to connect to the Internet.

For a class size of twenty-four students working in groups of 3, print
out eight copies of each website to be used in during the WebQuests.

b)
For each of the four topics being explored limit the number of websites that
address each topic to only two.

5.Students will work in groups of two or three to formulate potential experimental
questions to test various factors that affect the rate of enzyme activity.Experimental questions will be posted on either newsprint or an overhead
transparency.

WebQuest.Org Website that
describes how to develop and implement a WebQuest in the classroom.

Part 2: Inquiry Based Lab Activity (5 class periods)

Background Information:

Catalase will be used as the model enzyme to
investigate how temperature, enzyme or substrate concentration, salt
concentration and/or changes in pH affect the rate of enzyme action.Hydrogen peroxide is a toxic byproduct of metabolism.Catalase speeds up the breakdown of hydrogen peroxide into water and
oxygen gas.This enzyme can be found
in plant and animal cells as well as aerobic bacteria.The generation of oxygen gas bubbles can be used to quantitatively assess
the affect of various environmental conditions on the rate of catalase activity.

1.1. Students will
work in groups of two or three to:

(a)formulate a hypothesis to answer one of
the experimental questions posed by the class at the end of Part 1.

Once the instructor has
approved their hypothesis, the students in the group will begin to discuss
an experimental procedure to test their hypothesis.

(1)Homework:Students will complete their procedures at home.Students may conduct research using the Internet in order to design their
procedure.

(b)Students will review each others
procedures in class before deciding on a final procedure to submit to the
instructor for approval.

2.Once the instructor has approved the
procedure students will carry out their experiment during their assigned
laboratory period.

(a)Teacher Tips for Laboratory Preparation:

·
When reviewing student experimental procedures be sure that:

(1)
potato samples being tested are the same size

(a)
Students can use cork borers to obtain potato samples and trim them using a
scalpel or razor blade to the desired length.

(some students may
have an allergic reaction to latex so it is advisable to have a non-allergenic
substitute)

3.The students will be given time during the class period following the laboratory
activity to summarize their data and present their results to the class using
newsprint or overhead transparencies.Students will also be expected to complete the L section on the K-W-L
worksheet.

4.Teacher Preparation for Part 2:

a)Possible experimental procedures for this laboratory activity can be found by
reviewing the following:

·K-W-L
worksheet for each student on enzymes and characteristics of enzymes

·WebQuest
Worksheets for enzyme structure and function, models used to explain the
catalytic activity of enzymes, characteristics of enzymes and factors that
affect rate of enzyme activity

·Print copies
of websites used for the WebQuests

·Laptop
computers with Internet access

·LCD projector

·Overhead
projector

·Newsprint or
an overhead projector and transparencies to record student responses to the
K-W-L worksheet.

Part
2  Inquiry Based Lab

test tubes

gloves

test tube
rack

goggles

test tube
holder

Stop watch

Sharpie
marker

apron

10 mL
graduated cylinders

disposable
transfer pipettes

Potato
pieces or potato extract

1M
hydrochloric acid

Mortar and
pestle

1M sodium
hydroxide

Cosmetics
Grade Hydrogen peroxide - 40 volume (12% hydrogen peroxide)

vinegar

Sodium
chloride

400-mL
beakers

wash bottle
with deionized water

Ice

30
centimeter ruler

Alcohol
thermometers

hot plates

Newsprint
for presentation of results

blender

graph paper

4-ply
cheesecloth

ice bucket

cork borer
with 4 or 6-mm inside diameter

weighing
boats

Suggestions for
Assessment:

·Evaluate the
completion of the WebQuest worksheets.

·Evaluate the L
column for the K-W-L worksheet.

·Evaluate the group
presentation of data and results.

National
Science Education Standards:

1.National
Science Educations Standards  Grades 9 to 12

a) Science as Inquiry:

·Abilities necessary to do
scientific inquiry

·

Understandings about scientific inquiry

b)Life Science:

·
The Cell

c)K-12 Unifying Concepts and Processes:

·
Evidence, models, and
explanation

·
Change, constancy, and
measurement

Evolution and Equilibrium

New York State Standards:

1.Standard 1:Students will use mathematical analysis,
scientific inquiry, and engineering design, as appropriate, to posequestions, seek answers, and develop
solutions.

a)Key Idea 1 -
The central
purpose of scientific inquiry is to develop explanations of natural phenomena in
a continuing andcreative
process.

·Performance indicators 1.1, 1.2, 1.3

b)Key Idea 2 -
Beyond the
use of reasoning and consensus, scientific inquiry involves the testing of
proposed explanations involving
the use of conventional techniques and procedures and usually requiring
considerable ingenuity.

·Performance indicators 2.1, 2.2, 2.3, 2.4

c)Key Idea 3 -
The
observations made while testing proposed explanations, when analyzed using
conventional and inventedmethods, provide new insights into natural phenomena.

·Performance indicators 3.1, 3.2, 3.3, 3.4, 3.5

2. Standard 4:Students will understand and apply
scientific concepts, principles, and theories pertaining to the physicalsetting and living environment and
recognize the historical development of ideas in science.

a)Key Idea 1 - Living things are both similar to and different
from each other and from nonliving things.